Clinical Medical Assistant Exam Practice Question

Correct Answer: A

Rationale: Capillary blood sampling is most effective at the fingertip due to its rich supply of capillaries, allowing for quick and accurate blood collection. The fingertip is easily accessible and provides minimal discomfort for patients.

The elbow (B) is not preferred as it is primarily a venous site and can lead to larger blood volume collection, which is unnecessary for capillary sampling. The wrist (C) is also less suitable, as it has fewer capillaries and may cause more discomfort. The thumb (D), while it has capillaries, is often avoided due to its thicker skin and potential for more pain, making the fingertip the ideal choice for this procedure.